West African Coastal Area: Challenges and Outlook - The Land/Ocean Interactions in the Coastal Zone of West and Central Africa - page 18

by the mangroves, sea grass beds and coastal marshlands,
the importance of which is recognised.
• Self-maintenance services: constitution of habitats and of
the milieu. Maintaining of energy flows and nutritional
cycles through primary production, inter- and intra-eco-
system

The competition for access to these fishing
resources is intensified in a global context of
increasing demand, and access to pelagic resources
(but also to a lesser extent, demersal resources) is
coveted by foreign fleets—European fleets through
fishing agreements, but also Asian (Korea, China) and
Eastern European fleets. The way these foreign fleets
respect the access conditions is sometimes relative,
and the fiscalisation of the activity remains very
unequal, depending on the states and their foreign
partners.
While total catches have increased regularly since
1950, this growth should also be compared to the
regular increase in fishing efforts and the efficiency of
fishing units. The observed depletion of certain stocks
of demersal species, associated with the reduction in
the diversity of the communities, the sensitivity and
fluctuations recorded in certain specific fisheries, such
as cephalopods, closely dependent on the conditions
of the milieu (in particular of the upwelling), certainly
attests to a deterioration in the composition, structure
and organisation of marine biological communities.

services and functions, reproduction, nourish-

ment, etc.
• Provisioning services: fisheries (artisanal, staple, and
commercial), agriculture, firewood, ligneous and non-
ligneous gathered food products, aquaculture, crafts,
building (materials and service wood), pharmacopeia,
genetic resources, etc.
• Regulation services: climatic (carbon sequestration),
sediment trapping and coastal protection against marine
erosion and extreme marine weather events, treatment
and recycling terrigenous and effluent input from human
activities, waste water purification, protection against
floods from continental waters, stabilisation of mobile
dunes, etc.
• Cultural services: landscape appeal and environmental
quality (formation of beaches, islands and coastal land-
scapes), leisure activities (urban beaches for example),
research and education, cultural and religious heritage
(sacred sites, customs, traditional ways of life, artistic
expression), etc.
Not all of these ecosystem services, which strongly
contribute to the development potential of the coastal
countries, are subject to systematic economic valorisation to
date, except for a few sectors such as fishing. This also
implies that these services are globally still functional.
Nonetheless, the concerns related to coastal erosion show
that functional deficits in these natural systems can have a
considerable economic impact. The numerous instances of
deterioration observed along the West African coastal zone
are generally attributable to inappropriate development
practices implemented with no concern for the anticipation
of how the natural systems will respond (SDLAO, UE-
MOA-IUCN 2011 ).

Climate: Facing the Possible Futures

The uncertainty that characterises the future of these coastal
systems in a context is subject to climate change, which will
very probably have significant impacts on the state of the
coastal sea and the coast area.

West African Climate Models

There are systematic biases in the simulation of the African
climate by most of the climate models that contributed to
the 4th report of the IPCC (Intergovernmental Panel on
Climate Change). A total of 90 % of these models overes-
timate the precipitations on a large part of the continent
(Christensen et al. 2007 ). The temperatures simulated also
show bias, but this is not significant enough to call into
question the credibility of the projections. The intertropical
convergence zone simulated is moved towards the equator
in most of these models. The surface sea temperatures are
overestimated by 1 to 2 on the Gulf of Guinea. A large part
of these models have no monsoon, as they cannot properly
reproduce the northward movement of precipitations on the
continent. Only 4 of the 18 global ocean-atmosphere models
in the 4th IPCC report examined by Cook and Vizy ( 2006 )
are

Fishing: A major sector of activity, weakened by
fish stocks depletion
With an EEZ of more than two million km 2 , and
the existence of upwellings (essentially in Mauritania,
Senegal and the Gambia) rendering the waters highly
productive, fishing livelihoods are an essential com-
ponent of the development strategies of the coastal
States of West Africa, not only in building their GNP,
but also in the struggle to attenuate poverty and
malnutrition. Fishing is an important sector for
employment (approximately 600,000 jobs in Senegal,
more than 500,000 in Ghana).

able to produce quite realistically the interannual